This study is a randomized controlled trial of ipratropium bromide added to the routine treatment of asthma in a pediatric emergency department (PED). Ipratropium bromide (IB) is an anti-cholinergic medication which is given as an inhaled spray or nebulizer treatment and acts to relieve the bronchospasm of acute asthma. Evidence suggests that IB may improve pulmonary function when given in addition to standard beta-agonist bronchodilators. Few pediatric data are available, but a recent study of severe asthmatic children demonstrated a dose-realted improvement in pulmonary function related to the addition of IB. The present study is designed to measure the effects on clinical outcomes due to the addition of IB to routine asthma treatment. The study population are PED patients over 12 months of age who are being treated on an existing asthma treatment protocol. Subjects are randomly assigned to receive either IB (3 nebulized doses of 250 mcg) or saline in addition to albuterol aerosols and oral corticosteroids. Investigators and ED staff are blind to subject group assignment. Outcomes included the need for hospital admission as well as length and amount of treatment before discharge from the PED. Between July 27 and November 28, 1996, 250 patients were enrolled in the study. IB and control groups were similar in all baseline measures. Preliminary results demonstrate that IB group subjects ad 12% shorter treatment time before discharge (IB 186 min. vs control 211 min., p<0.02) and fewer total aerosols (IB 3.5 vs. control 3.8, p<0.05). Among patients with mild severity (by an initial severity score), IB subjects had 18% shorter treatment time (IB 155 min. vs. control 189 min., p=0.02). Admission rates did not differ significantly (IB 18.7% vs. control 22.6%, p=0.45). No adverse reactions were reported. The implications of this study are broad. Asthma is the most common chronic illness of childhood, and both prevalence and hospitalization rates have been rising over recent decades. Over 90 million dollars were spent on emergency room treatment of pediatric asthma in 1985 and costs have continued to increase. Improvements in treatment are needed to reduce the morbidity and cost of asthma. Ipratropium bromide is an inexpensive and safe medication which appears to reduce PED treatment time for children with acute asthma. Further patient enrollment and data analysis will define more clearly the effectiveness of this medication.